Oil and gas exploration company Tullow Oil has informed that the TEN project, offshore Ghana, is expected to deliver first oil within the next three to six weeks.
Tullow said on Thursday that the Tweneboa, Enyenra and Ntomme (TEN) Project off the west coast of Ghana remains on schedule and within budget and that it is now over 96% complete.
Hook-up and commissioning of the floating production, storage and offloading (FPSO) vessel, Prof. John Evans Atta Mills, connecting the pre-drilled wells to the vessel via the extensive subsea infrastructure, is nearing completion.
During July, Tullow said, the integrated start-up sequence is expected to be initiated with water injection to the Enyenra reservoir being followed by oil production. This sequence will then be repeated for the Ntomme reservoir.
A gradual ramp-up in oil production towards the FPSO capacity of 80,000 bopd is anticipated around the end of 2016 as the facilities complete performance testing and wells are brought up to optimum rates, said the company.
Tullow also said it estimates that TEN average annualised production in 2016 will be around 23,000 bopd gross (net: 11,000 bopd). Drilling is not expected to restart on the TEN field until after the resolution of the Côte d’Ivoire and Ghana border dispute through the ITLOS tribunal whose decision is expected in late 2017.
The associated gas produced at TEN will be re-injected into the Ntomme reservoir gas cap until gas export begins. Gas export was planned to start 12 months after field start-up, with the Tweneboa gas reservoir coming on stream a further 12 months later. However, according to Tullow, options to accelerate gas export are currently being evaluated as the fabrication of the gas export facilities is ahead of schedule and is expected to be complete in late 2016, some six months early.
Commenting today, Aidan Heavey, Chief Executive Officer, said: “After three years of hard work, I am delighted to say that the TEN Project is expected to deliver first oil within the next three to six weeks. This transformational project has remained on schedule and on budget since it began in 2013.”
Long-term solution for Jubilee FPSO issue
Tullow also said on Thursday that the issue with the turret bearing of the Jubilee field FPSO Kwame Nkrumah, identified in February 2016, has resulted in the need to implement new operating and offtake procedures.
This necessitated the FPSO be shut down for an extended period in April with production resuming in early May. Since then, the company said 18 offtakes to the storage tanker have been completed using a dynamically positioned shuttle tanker. Tullow said it expects to continue operating the field under these new procedures for the remainder of 2016 and anticipates average gross production to be around 85,000 bopd in the second half of 2016.
Tullow stated that based on the work undertaken over the past four months, the company and its partners now see converting the FPSO to a permanently spread moored facility, with offtake through a new deepwater offloading buoy, as the preferred long-term solution.
The partners are working with the Government of Ghana to seek their approval for this option and the first phase of this work will involve the installation of a stern anchoring system to replace the three heading control tugs currently in the field, the company said.
This is anticipated to be completed by the end of 2016 and will require short periods of reduced production. Tullow then plans a second phase of work to rotate the FPSO to its optimal spread moor heading in the first half of 2017. The work program covering these phases, which requires Government approval, is expected to cost $100-150 million gross and it is estimated that the Jubilee FPSO will need to be shut-down for 8-12 weeks during the first half of 2017, Tullow stated.
Upon completion of the spread mooring work program in mid-2017, the partners will review opportunities to improve the efficiency of offtake procedures, which may include the use of a larger dynamically positioned shuttle tanker, and seek to return production to levels seen before the turret issue occurred. The additional gross operating expenditure of the revised procedures is currently expected to be around $115 million for 2016 and $80 million for 2017.
A deep water offloading buoy is anticipated to be installed in the first half of 2018. This will remove the need for the dynamically positioned shuttle and storage tankers and the associated operating costs. Tullow noted that market enquiries are currently ongoing to estimate the cost and schedule for the fabrication and installation of this buoy.
Heavey said: “Production at Jubilee has stabilised with a gross rate in June of around 90,000 bopd. We have also made excellent progress on the long term solution to the turret issue, with the Jubilee Partners deciding that the optimum way forward is to spread moor the FPSO.”